In another call, a woman begs the dispatchers to send help, saying someone is "screaming and hollering" for help.

Moments later, she describes a light at the scene of the shooting.

"Oh my God ..." she said, "There's still somebody out there walking with a flashlight."

Zimmerman told police he shot the teen in self defense, authorities said, and remains free as the state attorney investigates. Police said he has not been charged because there are no grounds to disprove his story of what happened.

"The evidence and testimony we have so far does not establish that Mr. Zimmerman did not act in self-defense," the police chief said. "We don't have anything to dispute his claim of self-defense, at this point, with the evidence and testimony that we have."

Police released the tapes the same day the teen's relatives said the they are outraged that Zimmerman remains free.

"It's surprising. It's shocking," said Tracy Martin, the victim's father. "It lets me know that justice is just not being served here. All we want is justice for our son. We're not asking for anything out of the ordinary."

CNN has made numerous attempts to contact Zimmerman, but have been unsuccessful. It is unclear whether he has retained an attorney.

Some have accused Zimmerman, who is Hispanic, of profiling the black teen.

His father delivered a statement to the Orlando Sentinel this week saying his son moved out of his home after receiving death threats. George Zimmerman is Hispanic and grew up in a multiracial family, the statement says.